The present invention relates to packaged food products. More particularly, the present invention relates to microwave popcorn product articles characterized by having a thickened liquid oil fat component and to methods for filling such articles.
Broadly, the present invention is an improvement upon the microwave packaged food articles described in U.S. Pat. No. 6,013,291 “Microwave Popcorn With Liquid Fat and Method of Preparation (issued Jan. 11, 2000 to Brian Glass). The '291 patent describes microwave popcorn articles comprising food charges disposed within a microwave popcorn bag comprising unpopped or kernel popcorn and a quantity of liquid fat in addition to salt, flavor and other minor ingredients. The present invention is an improvement by substituting or including the thickened liquid fat compositions such as are described in U.S. Ser. No. 60/581,993 “VISCOUS FAT COMPOSITIONS HAVING LOW AMOUNTS OF TRANS-FAT, METHODS AND PRODUCTS” (filed Jun. 22, 2004 to David Plank) to provide improved product properties. Moreover, the desirable features of the '291 patent of providing a food product having low levels of trans fatty acids can be maintained.
Popcorn is a highly popular snack food item. In the past, the at-home preparation of popcorn by the consumer involved adding kernel popcorn plus a cooking oil to a covered pot and heating until the popcorn kernels popped to make popcorn. As used herein, “kernel popcorn” refers to unpopped popcorn. The noun “popcorn” or synonymously “popped popcorn” refers herein to popped kernel popcorn. The adjective “popcorn” can refer to either. Once prepared, common, relatively coarse, table salt is a frequently added flavoring or condiment. The resultant salted popped popcorn is a familiar snack food.
More recently, microwave popcorn products have become extremely popular. At present, in the U.S., over 70 different brands of microwave popcorn products are available. In general, the more popular microwave popcorn products comprise an expandable paper bag containing a charge of kernel popcorn, fat and salt. The microwave popcorn article is adapted to be heated in a microwave oven for three to five minutes to produce the popped popcorn. More recently, improved microwave popcorn articles have been fabricated employing a metallized susceptor which facilitates the heating of the kernel popcorn-fat charge and which, in turn, leads desirably to increases in popcorn volume and decreases in unpopped kernels. Microwave popcorn articles of this type are described in detail in, for example, U.S. Pat. No. 4,450,180 (issued May 22, 1984 to J. D. Watkins and incorporated herein by reference).
Microwave popcorn articles, of course, comprise a microwave popping bag and a charge of kernel popcorn, fat, and, usually, salt. Certain early patents taught the addition of kernel popcorn, fat and salt in the form of a prefabricated toroid or doughnut shaped piece. The piece was fabricated by mixing the kernel popcorn, salt and melted fat to form a blend and the blend was allowed to cool and harden into the toroid shape desired. These circular pieces were then dropped into the desired chamber of the popcorn bag prior to final sealing. (See for example U.S. Pat. No. 4,450,180, issued May 22, 1984).
Contemporary methods of filling microwave popcorn bags, however, employ a different filling process and technique. (See, for example, U.S. Pat. No. 4,604,854 entitled “Machine For Forming, Filling and Sealing Bags,” issued Aug. 12, 1986 to D. W. Andreas). The microwave bags having an unsealed open end are advanced to a first kernel popcorn filling station. While being maintained in an open position, the kernel popcorn is charged to the desired channel. Thereafter, the bags are advanced to a second filling station at which the fat/salt slurry is added to the bag. These products typically employ a hydrogenated fat that is solid at room temperatures. Prior to filling, the fat is heated to well above its melting point to form a liquid oil. Typically, the slurry is added in the form of a vertically dispensed pencil jet (i.e., a confined stream) of the slurry. Single station filling methods are also known that involve applying the fat/salt slurry as a spray onto the kernel popcorn as the kernel popcorn falls into the bag. (See, for example WO 95/01105 entitled “Reduced Fat Microwave Popcorn and Method of Preparation” published Jan. 12, 1995, or, equivalently, U.S. Pat. No. 5,960,979 issued Nov. 25, 1997) which is incorporated herein by reference. Such single station filling techniques are especially useful for the preparation of low fat microwave popcorn products.
The bags now containing both kernel popcorn and slurry are then advanced to a sealing station where the bags are provided with a top seal to complete the closure of the bag. The sealed popcorn bags are advanced to subsequent finish packaging operations which complete the folding of the bags, providing the bags with an overwrap, and inserting appropriate numbers of the bags into cartons, etc. As the heated fat cools and solidifies, a dimensionally stable food charge is formed that is resistant to oil leakage due to the fat being in a solid state.
Current varieties of microwave popcorn products include full fat products (e.g., 20-45% fat), reduced fat (10-20% fat) and low fat products (≦10%).
Regardless of fat content, conventional microwave popcorn products generally employ a partially hydrogenated vegetable oil (usually soybean oil) which is solid at room temperature. Hydrogenation increases oil stability and provides a solid oil or fat, which is less prone to wicking out of the bag during extended storage. A typical melting point range for such an oil would be about 37-40° C. While useful, hydrogenated high melting point fats have high concentrations of saturated fats and trans fatty acids. Current heath trends are concerned with the possible adverse health impact of consumption of saturated fats and trans fatty acids. Ingestion of saturated fats and trans fatty acids adversely affect serum cholesterol and have been linked as a causative for contributory factor in coronary heat disease. In some newer microwave popcorn products, traditional hydrogenated fats have been replaced with naturally occurring fats that are solid at higher than room temperatures (e.g., having melting points higher that 30° C.) such as palm kernel oil and thus do not require hydrogenation. While useful in that such naturally occurring fats are naturally low in trans fatty acids by avoiding hydrogenation, such naturally solid at room temperature fats are nonetheless generally high in undesirable saturated fats.
The '291 patent teaches employment of liquid oils in microwave popcorn products to overcome certain problems caused by production of microwave popcorn products during winter months using cold corn. Liquid oils are taught to be used to prevent manufacturing problems associated with premature congealing of melted hydrogenated fats upon contact with the cold corn. The '291 patent also teaches that another advantage of employing liquid oil is that the microwave popcorn prepared therefrom is desirably lower in undesirable saturated fat and trans fatty acids.
While useful, problems remain in preparing microwave popcorn products employing liquid oils. In particular, oil leakage or seeping can occur during distribution and storage. One solution is to employ a microwave popcorn bag fabricated with a oil and moisture impervious film layer in addition to the conventional bag layers (see for example, U.S. Pat. No. 5,679,278 “Microwaveable Container for Liquid Oils” issued Oct. 21, 1997 to David H. Cox) that is fabricated to provide a leak proof container. However, such a bag construction requires employment of a particular three ply bag laminated packaging roll stock as well as particular fabrication techniques to form a sealed microwave bag container in stead of the conventional two ply bag packaging roll stock. Such particular packaging material can add to the product costs. Also, current product production procedures employ high speed production lines and any added seal forming steps both require additional manufacturing equipment and can adversely impact line production speeds.
In view of the prior art and the problems described above, there is a continuing need for new and useful microwave popcorn products that that are reduced or low in fat that are low in saturated fat and trans fatty acids that nonetheless are resistant to oil leakage and seeping. Accordingly, it is an object of the present invention to provide microwave popcorn products containing liquid oil fat ingredients levels that are low in saturated fats and trans fatty acids.
In particular, it is an object of the present invention to provide methods for preparing full fat, reduced and low fat microwave popcorn products having at least a major portion of the fat component supplied by a thickened liquid oil.
Still another object of the present invention is to provide methods for preparing oil containing microwave popcorn articles that are resistant to oil leaking and seepage including articles comprising microwave popcorn bags that are fabricated from conventional two ply packaging stock.
Still another object of the present invention is to provide microwave popcorn fat components that are naturally low in trans fatty acids.
It has been discovered that the above objectives can be realized and superior microwave popcorn products provided by formulating food charge compositions disposed with conventional microwave popcorn bags, comprising popcorn, optionally salt and a thickened or viscous liquid oil in place of the typical solid oil. Such a liquid oil can have a melting point of ≦25° C. The oil can include an oil thickening ingredient such as a cyclodextrin in amounts sufficient to provide the desired degree of dimensional stability that minimizes oil leakage or seeping problems.